Drier.



F. HOOVER & A. J. MASON.

DRIER.

APPLICATION FILED JUNEQ, 1911.

1,()85,1 26, Patented Jan. 27, 1914.

2 SHEET S-SHEET 1.

F. K. HOOVER (in A. J. MASON.

DRIER.

APPLICATION FILED LTUNBQ, 1911. 1 085 126 Patented Jan. 27, 1914.

SHEETSSHEET 2.

UNITED STATES PATENT OFFICE.

FRANK x. HeovEIi. AND ARTHUR J. MASON, OF CHICAGO, ILLINOIS.

mama.

To all whom it may concern Be it known that we, FRANK K. HOOVER andARTHUR J. MASON, citizens of the United States, residing at Chicago, inthe county of Cook and State of Illinois, have invented certain new anduseful Improvements in Drier-s, of which the following is aspecification.

This invention relates to the general art of driers, and has referencemore particularly to a new and improved apparatus for eflecting thefinal drying of mineral matter that has previously been subjectedto-a'washing operation to cleanse it from foreign matter and impurities.

The device of our present invention has been designed more especiallyfor use in connection with, and to effect the final step of, a newprocess of treating a natural min eral product commonly known asphosphate rock, which is essentially a phosphate of lime that isextensively mined and marketed as a fertilizing agent. This naturalproduct exists to a considerable extent with a greater or less admixtureof clay, iron, sand and other foreignmatter or impurities; and in anapplication filed by us June 9, 1911, Serial No. 632,234, we have setforth and claimed the novel process of treatment above referred to,which consists essentially in the loosening, dissolving and finalrinsing out of the clay and other impurities from the particles ofphosphate rock. These operations, of course, involve the thoroughwetting of the material treated; and the final step in the said processconsists in drying by artificial means the purified product. The subjectmatter of the present application relates to an improved apparatus foreffecting this final drying operation.

In its main features the present apparatus comprises arotary tube ordrum that is disposed lengthwise of the firebox and smoke chamber of afurnace, and is disposed at a slight angle to the horizontal, so thatthe material fed in at one end will automatically flow slowly toward theother or discharge end; and this drum or tube is so constructed andmounted as to be subject both exteriorly and interiorly to the hot gasesand products of combustion of the furnace, and, furthermore, thecylindrical shell thereof is corrugated or scalloped longitudinally,which has the double function of increasing the area of its heatingsurface, and also providing a simple means for effecting Specificationof Letters Patent.

Application flied June 9, 1911.

Patented J an. 2'7, 1914.

Serial No. 632,239.

a thorough agitation and tumbling of the material during its passagethrough the :drum which facilitates the passage of the i hot gasestherethrou'gh. The drum is preferably hung by wire cables at its endsfrom an overhead rotating shaft to which power is applied; but,obviously, the manner and means of driving the drum may be varied asdesired. In association with this device for applying furnace heat, wepreferably employ a device for effecting a preliminary draining of thematerial by which a considerable percentage of the total moisture isextracted before the material is subjected to 1 the artificial heat.

Our invention, its principle and mode of operation, and the benefits andadvantages secured thereby will be readily understood when considered inconnection with the accompanying drawings, which illustrate onepractical form in which the invention may be embodied and wherein-Figure 1 is a central vertical section through the drainer and the feeddevices leading therefrom into the rotary drum of the drier. Fig. 2 is avertical longitudinal section through the furnace. showing the drum ofthe drier mounted therein and partly broken out to show its internalconstruction, and also showing the drum supporting and driving means.Fig. 3 is a cross-section on the line 3 3 of Fig. 2.

Referring to the drawings, and first briefly describing the drainingmechanism, which is preferably, though not necessarily, employed as apart of the complete drier, 5 designates each of a pair of tanks havingin their bottoms discharge openings 6, formed by tubes set in thebottoms of the tanks and extended up through a body 7 of filteringmaterial. The drainage water escapes through a drain pipe 8, while tubes6 are equipped with controlling valves 9, that are opened from time totime to permit the drained material to pass into an underlying hopper10. lVhen the drainage tank has been filled with the washed phosphaterock and given time for drainage, and is ready for the drying operation,we find that it has assumed a condition so water-packed that it will notflow even when a very large opening as large as three feet in diameteris made in the floor of the tank or receptacle. In order to cause it toflow out of the tank, we first bore a hole through the exit opening 6from below upwardly to the full height of the material in the tank, asshown in Fig. 1, using for this purpose an earthboring auger ofsufficient size (actually about nine inches in diameter). The materialis then shoveled from the top into this hole and passes thence into thehop-- perlO. While it is true that this material packs in the mannerabove described, yet after it has been drained and once loosened itremains in the loose condition, like ordi nary building sand, and flowsfreely in any desired manner. The expeditious removal of the drainedphosphate rock from these draining-tanks has heretofore presented quitea serious problem; but operating in the manner above described thematerial is easily removed and the capacity of a single operator becomesvery great, as high'as ten tons per hour. The hopper 10 is equipped witha delivery roller 11, adapted to effect a regulable feed of the materialthrough a discharge chute 12 into the receiving end of the drier tube ordrum 13. This latter, as will be seen by'reference to Fig. 2, is locatedwithin and longitudinally of a Well known type of boiler heating furnacedesignated -as an entirety by 14. This heating tube or drum is made upof'a plurality of cast-iron sections united end to end; and it will benoted as a special feature of construction that the cylindrical surfaceof this drum is not a plain circle in crosssection, but is made in theform of a plurality of scallops, 13, as best shown in Fig. 3. Thisconstruction very considerably increases the total area of the heatingsurface;

and, further, the scallops constitute local chambers or pockets, which,as the drum revolves, serve to pick the material up and tumble it uponitself, thus producing a continuous state of agitation, most favorableto the thorough penetration of the entire body of material by theconducted heat and the hot gases, and the release of the steam particlesgenerated therein.

The discharge end of the tube is blanked, and near said end thecylindrical surface is provided with an annular row of apertures 15,which serve the double function of cffecting the discharge of the driedmaterial and permitting the entrance of the hot gases and products ofcombustion, which flow back through the interior of the drum, and areled thence through a casing 16 underlying the feed devices and a flue 17to thev chimney. It will thus be seen that the drum is subjected to theheat of the gases and products of combustion both externally andinternally. The greater part of the dry-- ing is accomplished merely bythe contact of the material with the heated metal which receives itsheat largely from the external exposure. The hot gases fiow from thefirebox externally of the drum to its discharge end, and thence passinto the drum through rosarae the same holes 15, which afford exit tothe dry material. v

For supporting and slowly rotatin the drum we have shown an overhead sha18, journaled in suitable bearings 19, and carrying at its ends pulleys20, over which are trained wire slings 21 that engage similar pulleys 22on the ends of the drum 13. The shaft.18 is driven by a gear 23 thereonengaged by a pinion 24 on a counter shaft 25, thi latter being belted toa source of power through pulley 26. To support the drum 13 at a slightincline and in proper driving relation to its overhead driving devices,we provide an anti-friction stop or abutment in the form of a roller 27j'ournaled in a vertical bearing 28, secured to the front wall of-thefurnace and engaging a fiange22 on v the front pulley 22.

As above stated the apparatus is complete for many practicalpurposeswithout the a furnace simply through a constantly rotating metal tube ordrum, the contact of the material with the hot gases being relied on toefi'ect the drying. In the device of our invention this tube or drum isheated both externally and internally by the'hot gases, and the dryingof the material is principally eflected simply by contact of the wetmaterial with the highly heated metal of the drum. Each section of thedrum is a single integral piece of cast iron, by reason I of which theheat conduction is more perfect than in the case of a built-upstructure. In addition, it is well known that cast-iron will withstandthe effect of high temperatures and variations in temperature below 1800F. much better thanwrought iron.

We claim:

1. In a drier of. the character described, the combination with afurnace, of a drier tube the cylindrical wall of which is of scallopedform in cross section mounted therein and extending longitudinallythereof at an angle to the horizontal, said tube being closed at,andformed in the bottoms of the v scallops with a row of aperturesadjacent to,

bustion from the furnace chamber to the 1 interior thereof, means forrotating said tube, and meansto supply the material to be dried to thefront end of said tube, substantially as described.

2. In a drier of the character described, the combination of a drainingdevice, a hopper into which the drained material is discharged, afurnace, a drier tube rotatably mounted in said furnace, and means foreffecting a regulable feed of the material from said hopper into one endof said drier tube, substantially as described.

3. In a drier of the character described, the combination of a drainingdevice, a hopper into which the drained material is discharged, afurnace, a rotary drier tube extending through the fire-box of saidfurnace and formed near the discharge end 15 with an annular row ofopenings for the discharge of the material and the ingress of the hotgases of combustion, means for effecting a regulable feed of thematerial from said hopper into the receiving end of said drier tube, acasing underlyingsaid hopper and feeding means and commnnieat= ing withthe receiving end of said drier tube, and a smoke flue communicatingwith the upper portion of said casing, substantially as described.

FRANK K. HOOVER ARTHUR J. MASON. \Vit-nesses:

SAMUEL N. POND, C. A. KENYON.

